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authorDerek Hower <drh5@cs.wisc.edu>2009-11-13 09:43:39 -0600
committerDerek Hower <drh5@cs.wisc.edu>2009-11-13 09:43:39 -0600
commit2ee04d65873bac7a91d9d309eff79d13b8cc8103 (patch)
tree710f231e542986a01bf48cdd42f510b7f2531408 /src/mem
parentceb8fde914aebc3568d55d50defb8aed36717ea6 (diff)
downloadgem5-2ee04d65873bac7a91d9d309eff79d13b8cc8103.tar.xz
ruby: reduce the memory usage of ruby by making memory vector page based
Diffstat (limited to 'src/mem')
-rw-r--r--src/mem/ruby/system/MemoryVector.hh72
1 files changed, 58 insertions, 14 deletions
diff --git a/src/mem/ruby/system/MemoryVector.hh b/src/mem/ruby/system/MemoryVector.hh
index c5f3cea7f..775244840 100644
--- a/src/mem/ruby/system/MemoryVector.hh
+++ b/src/mem/ruby/system/MemoryVector.hh
@@ -21,61 +21,105 @@ class MemoryVector {
void write(const Address & paddr, uint8* data, int len);
uint8* read(const Address & paddr, uint8* data, int len);
- private:
- uint8* getBlockPtr(const Address & paddr);
+private:
+ uint8* getBlockPtr(const PhysAddress & addr);
uint32 m_size;
- uint8* m_vec;
+ uint8** m_pages;
+ uint32 m_num_pages;
+ const uint32 m_page_offset_mask;
};
inline
MemoryVector::MemoryVector()
+ : m_page_offset_mask(4095)
{
m_size = 0;
- m_vec = NULL;
+ m_num_pages = 0;
+ m_pages = NULL;
}
inline
MemoryVector::MemoryVector(uint32 size)
+ : m_page_offset_mask(4095)
{
- m_size = size;
- m_vec = new uint8[size];
+ setSize(size);
}
inline
MemoryVector::~MemoryVector()
{
- delete [] m_vec;
+ for (int i=0; i<m_num_pages; i++) {
+ if (m_pages[i] != 0) {
+ delete [] m_pages[i];
+ }
+ }
+ delete [] m_pages;
}
inline
void MemoryVector::setSize(uint32 size)
{
+ if (m_pages != NULL){
+ for (int i=0; i<m_num_pages; i++) {
+ if (m_pages[i] != 0) {
+ delete [] m_pages[i];
+ }
+ }
+ delete [] m_pages;
+ }
m_size = size;
- if (m_vec != NULL)
- delete [] m_vec;
- m_vec = new uint8[size];
+ assert(size%4096 == 0);
+ m_num_pages = size >> 12;
+ m_pages = new uint8*[m_num_pages];
+ memset(m_pages, 0, m_num_pages * sizeof(uint8*));
}
inline
void MemoryVector::write(const Address & paddr, uint8* data, int len)
{
assert(paddr.getAddress() + len <= m_size);
- memcpy(m_vec + paddr.getAddress(), data, len);
+ uint32 page_num = paddr.getAddress() >> 12;
+ if (m_pages[page_num] == 0) {
+ bool all_zeros = true;
+ for (int i=0;i<len;i++) {
+ if (data[i] != 0) {
+ all_zeros = false;
+ break;
+ }
+ }
+ if (all_zeros) return;
+ m_pages[page_num] = new uint8[4096];
+ memset(m_pages[page_num], 0, 4096);
+ uint32 offset = paddr.getAddress() & m_page_offset_mask;
+ memcpy(&m_pages[page_num][offset], data, len);
+ } else {
+ memcpy(&m_pages[page_num][paddr.getAddress()&m_page_offset_mask], data, len);
+ }
}
inline
uint8* MemoryVector::read(const Address & paddr, uint8* data, int len)
{
assert(paddr.getAddress() + len <= m_size);
- memcpy(data, m_vec + paddr.getAddress(), len);
+ uint32 page_num = paddr.getAddress() >> 12;
+ if (m_pages[page_num] == 0) {
+ memset(data, 0, len);
+ } else {
+ memcpy(data, &m_pages[page_num][paddr.getAddress()&m_page_offset_mask], len);
+ }
return data;
}
inline
-uint8* MemoryVector::getBlockPtr(const Address & paddr)
+uint8* MemoryVector::getBlockPtr(const PhysAddress & paddr)
{
- return m_vec + paddr.getAddress();
+ uint32 page_num = paddr.getAddress() >> 12;
+ if (m_pages[page_num] == 0) {
+ m_pages[page_num] = new uint8[4096];
+ memset(m_pages[page_num], 0, 4096);
+ }
+ return &m_pages[page_num][paddr.getAddress()&m_page_offset_mask];
}
#endif // MEMORYVECTOR_H